This invention relates to the art of dispensing dry particulate solid materials into bags by means of air flow bag packers. More particularly, it relates to a spout and hood assembly designed to control dust and relieve pressure from within bags such as paper and polyethylene valve bags as they are filled with such solid materials from a conventional air flow packer.
The need for this invention arose because of the difficulty of filling polyethylene bags with carbon black at an acceptable rate. Additionally, stringent environmental regulations dictated that escaping dust be controlled.
In the carbon black industry, the carbon black from the reactors is separated from the waste gases in bag filters, after which it is pelletized, dried, and placed into storage. From storage it is shipped for sale either in bulk or in bags. For bag shipments, the dry pellets are usually fluidized with air in an air flow packer such as the apparatus described in U.S. Pat. No. 3,083,780 and then discharged into bags.
During the bag-filling operation, the bags become filled with air, and it is therefore important to discharge the air from within the bag not only to control the amount of dust from the pellets but to prevent the bag from bursting. The objects of this invention are to eliminate or minimize these problems.